The relationships of chronic alcoholism, zinc deficiency, and folate metabolism are studied in patients with chronic alcoholic liver disease, and in a rat model including four feeding groups: Control (C), control substituted with 36% of calories as ethanol (C plus E), zinc deficient (ZD) and zinc deficient substituted with ethanol (ZD plus E). Measurements are made in the patient model of plasma, urinary, and hepatic zinc, and of the intestinal absorption of two labeled folates (3H-pteroylmonoglutamate and 14C-pteroylhexaglutamate). Measurements in the rat model include tissue levels of zinc and folate, activities of intestinal and hepatic folate conjugase and hepatic methionine synthetase, identification of hepatic folates, and the intestinal absorption of the same two labeled folates.